Radio base stations (RBS) generally have some connection or terminal for local management (OAM), where a site technician on site may change settings, check status and upload/download files (like software, logs, scripts). This is used when a site technician physically visits an RBS site in order to install/repair/modify/maintain/check/troubleshoot the RBS. The main reasons for having a local OAM connection are:    Convenience: There is often a remote OAM connection too, but that terminal may be located in a control centre far, far away—while the RBS is close. Hence it is a logical convenience to be able to connect to a local terminal.    Availability: A remote OAM connection depends on a transport connection for OAM to be active and working. Hence it may be unavailable. A local connection at the RBS and/or RBS site is more reliable and easier to keep available even during installation/repair etc. when parts of the RBS and/or the transport network for the RBS may be inactive, broken or not yet installed.
Typically, an OAM terminal is connected to the RBS via a wire. A typical terminal is a standard laptop with a standard web browser and/or special OAM software, or a SmartPhone or special hardware, with means to wiredly connect to the RBS and control/monitor the RBS.
It has to be possible to connect the OAM terminal to the RBS. This conflicts with the desire to install RBS's at locations that are cheap and/or has good radio coverage. In general, an RBS should be in a high location (to get coverage), in a location far away or where it is hard to reach or get access (to get cheap rent).
This conflict between easy physical access and RBS location increases due to RBS's becoming smaller and cheaper and the need to fit more RBS's closer to people in order to get more bandwidth for mobile broadband, hence they are often mounted at hard-to-reach-places like, close to or even inside the antenna i.e. at the top of an antenna tower or at high buildings, inside elevator and ventilation shafts, several meters up on walls, light poles etc. i.e. using space that is not needed by humans and vehicles in a crowded city where any useful space has a premium price tag.
There may also be working security considerations as an RBS located in the antenna may be dangerous to go near when the transmitter is on.